Enzymes are a group of proteins that catalyze a variety of typical biochemical reactions and have been employed in cleaning compositions since early in the 20th century. It was not until the mid 1960's when enzymes were commercially available with both the pH stability and soil reactivity for detergent applications. Enzymes are known as effective chemicals for use with detergents and other cleaning agents to break down soils. Enzymes break down soils making them more soluble and enabling surfactants to remove them from a surface and provided enhanced cleaning of a substrate.
Enzymes can provide desirable activity for removal of protein-based, carbohydrate-based, or triglyceride-based stains from substrates. As a result, enzymes have been used for various cleaning applications in order to digest or degrade soils such as grease, oils (e.g., vegetable oils or animal fat), protein, carbohydrate, or the like. For example, enzymes may be added as a component of a composition for laundry, textiles, cleaning-in-place, drains, floors, carpets, medical or dental instruments, meat cutting tools, hard surfaces, personal care, or the like. The use of enzyme products have evolved from simple powders containing alkaline protease to more complex granular compositions containing multiple enzymes and still further to liquid compositions containing enzymes. In addition, significant progress has been made to obtain enzymes retaining stability under alkaline conditions, such as the presence of detergent builders and other detergent compositions. See e.g. U.S. Pat. Nos. 4,771,003, 4,529,525, 4,480,037 and 4,052,262, each of which are herein incorporated by reference in its entirety. Despite such advances there remains a lack of consistent stability under highly concentrated conditions for enzyme and detergent formulations and/or long-term storage of shelf stability.
In addition, there remains a need for cleaning applications using enzymes under high temperature conditions. Most proteases and other enzymes are unable to survive at elevated temperatures, typically unable to survive temperatures above about 140° F. to about 150° F. Upon exposure to such elevated temperatures, the enzyme is denatured or damaged, such that there is a change in the configuration of the structure (although not limited to a particular theory as one skilled in the art shall ascertain) and as a result the enzymes are unable to be used in numerous desirable cleaning applications. Enzyme instability due to decomposition caused by either denaturation or by proteolysis (self-digestion) are well established limitations to the use of enzymes in cleaning compositions. Methods for stabilizing enzymes over extended periods of time and for exposure to heat, causing reduced enzyme stability, remain as current limitations of enzymes.
Accordingly, it is an objective of the invention to develop methods to permit the use of enzymes to remove soils under high temperature conditions, such as ware wash applications.
A further object of the invention is to develop methods for stabilizing and activating thermally labile enzymes.
A still further object of the invention is to develop compositions for the stabilization and activation of thermally labile enzymes for use in high temperature conditions, including for example warewash applications.